Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
canh manh » lanh manh, canh tranh, cach mang
cong cong » cong dong, trong cong, dung cong
manh cua » doanh cua, ban cua
tan toan » tan tran, van toan, dan toan
tap toan » tap doan, tap quan
bai toan » bai tap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hien xanh - canh manh cua cong cong ((tan toan) or (((tap toan) OR (bai toan)))) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - canh manh cua cong cong ((tan toan) OR (((tap toan) OR (bai toan)))) cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - canh manh cua cong cong ((tan toan) or (((tap toan) OR (bai toan)))) cau*".